Klin, I think you should contact some NGOs: "CELS" and "Poder Ciudadano".
The CELS is the NGO of abuelas de Plaza de Mayo and Estela de Carloto
http://en.wikipedia.org/wiki/Estela_Barnes_de_Carlotto
Estela de Carloto was a kindergarden teacher when her daughter who was pregnant was kidnapped. Her grandson who was born in an illegal maternity (under military jurisdiction) is still missing. Her husband was kidanapped too, tortured and release after the payment of a randsom to the military criminals.
This is the CELS website:
http://www.cels.org.ar/home/index.php?info=&ids=&lang=en&ss=
They are responsible for the trial against the military who were involved in crimes against the humanity. I also think that "abuelas" are responsible for the stop of political violence in this country.
You will find out that this is a very sophisticated NGO and they might be a little nasty and/or arrogant.
Poder Ciudadano is the other NGO I suggest you contact. They are related to Transparency International and this NGO was founded by Luis Moreno Ocampo.
http://poderciudadano.org/
http://en.wikipedia.org/wiki/Luis_Moreno_Ocampo
Those are the 2 most prestigious NGO about Human Rights and the most professional.
I suggest you avoid "Madres de Plaza de Mayo" which is related to Hebe de Bonafini.
http://en.wikipedia.org/wiki/Hebe_de_Bonafini
she is a bit extremist -and crazy- but it is understandable as soon as her 2 sons and a daughter are desaparecidos. I think that her organization is still living in the 70's with all its defects.
CORREPI is another NGO to avoid. They are focus on illegal police assesination and torture. They have this extreme left idea about to show the defects of the capitalism as a way to open minds for the revolution.
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There is another you can visit:
La Asamblea Permanente por los Derechos Humanos:
http://www.apdh-argentina.org.ar/
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Regarding the off topic, I don t believe about the Theory of the two demons.
http://en.wikipedia.org/wiki/Theory_of_the_two_demons
However, even there were several crimes commited by members of Montoneros or ERP or whatever, they can be prosecuted only of they were commited with the help or the acquiescence of the State during democracy. Otherwise, they are prescribed.
If the crimes were commited during the dictadura, they might be legal depending on the facts.
National Constitution:
Artículo 21.-
Todo ciudadano argentino está obligado a armarse en defensa de la patria y de
esta Constitución, conforme a las leyes que al efecto dicte el Congreso y a los decretos del Ejecutivo nacional.
Artículo 36.-
Esta Constitución mantendrá su imperio aun cuando se interrumpiere su observancia por actos de fuerza contra el orden institucional y el sistema democrático. Estos actos serán insanablemente nulos.
Sus autores serán pasibles de la sanción prevista en el Artículo 29, inhabilitados a perpetuidad para ocupar cargos públicos y excluidos de los beneficios del indulto y la conmutación de penas.
Tendrán las mismas sanciones quienes, como consecuencia de estos actos, usurparen funciones previstas para las autoridades de esta Constitución o las de las provincias, los que responderán civil y penalmente de sus actos. Las acciones respectivas serán imprescriptibles.
Todos los ciudadanos tienen el derecho de resistencia contra quienes ejecutaren los actos de fuerza enunciados en este artículo.
The assesination of Rucci is a good example of a crime that might be prosecuted as soon as there were montoneros in the government of Provincia de Buenos Aires who, being diputes, worked on the operation traviata during democracy. (I suggest the reading of "Operacion Traviata")
In fact, there is a case open at the Federal Court.
Other example is:
The attack to the Barracks of Infanteria de Monte in Corrientes, "Operacion Primicia" (I suggest the reading of "Operacion Primicia" and "Montoneros, la arrogancia armada".)
http://es.wikipedia.org/wiki/Operacion_Primicia
Resuming: 1) those crimes can be only being prosecuted if they were commited during democracy 2) They were done with help or the acquiescence of the State.
Regards